The present invention relates to a seat belt device to protect a driver and passenger upon a collision, and specifically to an air belt device with a part of the seat belt made like a bag that is inflated by the gas supplied from a gas generator. More specifically, this invention relates to an air belt device with a safety measure for malfunctions of the gas generator.
Air belt devices have been known as disclosed by the Japanese Unexamined Pat. Publication No. 85301, etc. FIG. 12 (a) is a general perspective view of the air belt device of this Pat. publication and FIG. 12 (b) is a cross sectional view along the line B--B of FIG. 12 (a).
The air belt device 1 comprises a shoulder belt 2 which extends from right to left of a driver and passenger, a wrap belt 3 which extends from right to left of a driver and passenger, a buckle 4 which is provided on a vehicle floor, a tongue 5 which is inserted into the buckle 4 when fastening the air belt, and an intermediate guide 6 to guide the shoulder belt 2.
The shoulder belt 2 comprises a normal belt 2a similar to a prior common seat belt and a bag-like belt 2b connected to one end of the normal belt 2a. The normal belt 2a is movably guided by the intermediate guide 6. The other end of the normal belt 2a is connected to a seat belt retractor (ELR) 7 with an emergency lock device fixed to a vehicle body. The normal belt 2a can be taken up around the seat belt retractor 7.
The bag-like belt 2b is positioned to contact on a driver and is connected to the tongue 5 in another end opposite to the end connected to the normal belt 2a.
The wrap belt 3 is made of a normal belt similar to a common seat belt with one end fastened to the tongue 5 while the other end is secured to the seat belt retractor (ELR) 8 fixed to a vehicle body. Further, the buckle 4 is coupled with the gas generator 9 which operates upon an emergency such as a vehicle impact and ejects a high pressure gas.
The tongue 5 and buckle 4 have a passage to lead the gas from the gas generator 9 to the bag-like belt 2b.
The main part 2c of the bag-like belt 2b of the shoulder belt 2 is, as indicated by a solid line in FIG. 12 (b), normally held like a belt by holding the main part 2c, covering it by a cover 2d and sewing up at both ends 2e. When the gas generator 9 is activated, the sewed up ends 2e of the cover 2d are easily separated by inflation of the shoulder belt 2 and the bag-like belt 2b expands as indicated by an alternate long and two short dashes line. In the prior air belt device 1 described above, when the gas generator 9 is activated while the tongue 5 is not inserted into the buckle 4, gas is ejected upward from the buckle 4.